Hydraulic dredge



JURY 3, 1934-. A, KERTZMAN 1,964,951

HYDRAULIC DREDGE Filed Sept. 1, 1935 Patented July 3, 1934 UNITED STATESPATENT OFFICE 8 Claims.

'It is the object of this invention to provide an hydraulic dredge withnovel means for separating much of the finer excavated material from thecoarse material.

A particular object is to provide a dredge with an intake hood, aplurality of suction pipes connected to said hood and means in the hoodfor excluding the coarser excavated material from one of said pipes sothat there is a separation of the coarser from the finer material withinthe hood and the different classes of material are conveyed to suitableplaces of disposal through separate pipes.

In the recovery of sand and gravel it is frequently found that an excessof sand over gravel is present in the pit and heretofore the perationsof separating the excess sand from the coarser material and disposing ofsuch sand have been relatively expensive and wasteful operations. Withmy improved dredge I effect substantial economies by separating theexcess sand from the coarser material at the intake hood of the dredgeand dispose of such excess by means of an auxiliary conduit and pumpwhich are adapted to deposit the fine material, separate from the coarsematerial, at any convenient place.

The invention will be best understood by reference to the accompanyingdrawing in which,

Fig. 1 is a diagrammatic view illustrating my improved dredge;

Fig. 2 is an end view of the intake hood, and

Fig. 3 is a central, vertical section through the hood and adjacentportions of the conduits for the different classes of material.

An intake hood 4 has an oblique, open side 5 and is divided intochambers 6 and '2 by a screen 8 adapted to allow the passage of the sandor finer material into the chamber 7 and to exclude the coarser materialtherefrom. A main dredge pipe 9 communicates with the lower chamber 6and a smaller pipe 10 communicates with the chamber '7. Secured to oneside of the hood 4 is a hook-like arm 11 having its free endapproximately at the center point of the intake end of the pipe 9 toguard against the entry of excessively large bodies or rocks into saidpipe. The main dredge pipe 9 has a flexible section 12 and communicateswith the intake of a power-driven pump 13. An outlet pipe 14 for thepump 13 extends to the place of disposal for the main body of theexcavated material.

From the hood 4 the auxiliary pipe 10 extends in parallel relation tothe pipe 9 and communicates with an auxiliary pump 15 having an outletpipe 16 extending to the place of disposal for the fine material. Aflexible section 1'? of the pipe 10 and the flexible section 12 of thepipe 9 permit the necessary movements of the suction pipes and hood 4for dredging. During the dredging the hood 4 and pipes 9 and 10 may bemoved about in the usual manner by a crane having connections with thepipes 9 and 10, as indicated by the cable 18 and hanger 19 shown inFig. 1. The diagrammatic representation of a barge or other dredgesupport is indicated by the numeral 20 ll; 1 and a submerged gravel pitis indicated An opening 22 in the top of the hood 4 is arranged to admitwater to the chamber '7 under 7 control of a closure 23. This closure isslidable to and from the opening 22 between parallel guide bars 24 andmay be moved to various positions to regulate the amount of materialdrawn through the screen 8.

In the operation of my dredge, the hood 4 is lowered into the water inthe pit so as to cause the open side 5 of the hood to rest on thematerial to be recovered and the pumps 13 and 15 are simultaneouslyoperated to create a partial vac- 8 uum in the pipes 9 and 10. The pump13 supplies the principal power for drawing the material into the hood 4and the pump 15 is merely required to exert sufficient suction in theupper chamber to draw the desired part of the finer material up throughthe mesh of the screen 8, leaving the coarser material to be drawn intothe pipe 9. The finer material is conducted to any convenient place ofdisposal through the pipe 16. It is sometimes returned to the body ofwater back of the dredge. The pipe 14 delivers the gravel or othermaterial to be recovered to the place of disposal or treatment in theusual manner.

It will now be understood that my improvements do not interfere with thenormal operation of the main dredge and that the capacity of theapparatus for recovering the selected material is substantiallyincreased while much of the trouble and expense heretofore attendantupon the separation and disposal of the excess of fine material isobviated.

Having described my invention, what I claim as new and desire to protectby Letters Pat- 5 ent is:

1. A dredge having in combination an intake hood, a plurality ofconduits for excavated material communicating with said hood, meansarranged in said hood to bar the passage of the coarser excavatedmaterial to one of said conduits and means for creating suction in saidconduits.

2. In an hydraulic dredge, an intake hood, a plurality of conduits forexcavated material communicating with said hood, a screen mounted insaid hood to bar the passage of the coarser excavated material to one ofsaid conduits, pumps severally arranged to create suction in saidconduits and discharge pipes severally connected to said pumps fordisposing of the excavated material.

3. In an hydraulic dredge, an intake hood, two conduits for excavatedmaterial communicating with said hood, a main pump for drawing thecoarser material into said hood and through one of said conduits, anauxiliary pump connected to the second conduit and means in said hoodadapted to bar the passage of the coarser material to said secondconduit while allowing the passage of the finer material thereto.

4. In an hydraulic dredge, an intake hood, large and relatively smalldredging conduits communicating with said hood, means in said hood forbarring the passage of the coarser material to said smaller conduit, amain pump connected to said larger conduit for drawing material intosaid hood and through said larger conduit and an auxiliary pumpconnected to said smaller conduit for withdrawing the finer materialfrom said hood and through said smaller conduit.

5. In an hydraulic dredge, an intake hood having a normally lower, openside, a screen dividing said hood into upper and lower chambers, adredge pipe communicating with said lower chamber, a second dredge pipecommunicating with said upper chamber and means for creating suction inboth of said pipes.

6. In an hydraulic dredge, an intake hood having a normally lower, openside, a screen dividing said hood into upper and lower chambers, a maindredge pipe communicating with said lower chamber, an auxiliary dredgepipe communicating with said upper chamber above said screen and pumpsfor severally creating suction in said main and auxiliary pipes so as todraw the finer excavated material through said screen into said upperchamber and auxiliary pipe and to draw the coarser material through saidmain pipe.

'7. In an hydraulic dredge, an intake hood having a normally lower, openside, a screen dividing said hood into upper and lower chambers, a maindredge pipe communicating with said lower chamber, an auxiliary dredgepipe communicating with said upper chamber, means for creating suctionin said main and auxiliary pipes, said upper chamber having an openingfor the admission of water thereto, and means for controlling the flowof water through said opening.

8. In an hydraulic dredge, an intake hood, main and auxiliary dredgingconduits communicating with said hood, means in said hood for barringthe passage of the coarser material to said auxiliary conduit, a mainpump connected to said main conduit for drawing material into said hood,an auxiliary pump connected to said auxiliary conduit for withdrawingthe finer material from said hood through said auxiliary pipe, a by-passfor admitting water to said hood and auxiliary pipe and means forcontrolling the flow of water through said by-pass.

ALBERT KER'IZMAN.

